Description. The circuit presented her will transmit a audio tone in the FM band. The circuit can be used as a tracking signal transmitter or a remote control transmitter. The circuit uses only easily available components and any one... read more

Description. Many fire alarm circuits are presented here,but this time a new circuit using a thermistor and a timer to do the trick. The circuit is as simple and straight forward so that, it can be easily implemented. The... read more

Description. This straight forward circuit will protect electrical appliances from over voltage as well as under voltage. The circuit also produces an alarm when the power supply comes back. An ideal circuit for home to protect your valuable equipments... read more

Description. Here is a simple variable frequency circuit based on timer NE555. Here NE55 is wired as an astable multivibrator, whose output frequency can be varied by varying a potentiometer. This circuit is a must in the work bench... read more

Description. A simple scoring game circuit that can be used for all occasions when a dice is needed.The circuit is based on a NE555 timer,a 74LS192 counter,a74LS247 decoder and a & segment LED display.The timer IC1 will produce the... read more

A simple Light to Frequency Converter Introduction. Here is the circuit diagram of a effective light to frequency converter circuit that can be used for variety of applications such as light intensity measurement,fun etc. The circuit is based on... read more

Description. A dual tone train horn simulator circuit can be made using two NE 555 timers connected in cascade.Here instead of using two NE 555 timers a single NE 556 timer is used which is a nothing but two... read more

InfraRed (IR) Sensor/Detector Circuit Description. The circuit shows that the output of IC1 555 IC,which is designed for a duty cycle of 0.8mSec,with a frequency of 120Hz and 300 mA peak current, is used to drive the infra red... read more

Fridge Door Alarm Circuit Description. This is a fridge door alarm circuit, which produces an audible alarm when fridge is left open for a preset time. This versatile alarm is based on two 555 timer IC’s. Both ICs are... read more